Although its exact mechanisms of action in this application are unknown, verapamil exerts a vasodilatory effect on cerebral arteries and interacts with serotonergic systems involved in migraine pathogenesis. Verapamil is a phenylalkylamine calcium channel blocker used in the treatment of high blood pressure, heart arrhythmias, and angina, 16 and was the first calcium channel antagonist to be introduced into therapy in the early 1960s. Your doctor may occasionally change your dose. Headache. Drinking alcohol with verapamil can cause side effects.Avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Use of any information is solely at the user's own risk. Learn verapamil with free interactive flashcards. Verapamil for Cluster Headache. See In clinical trials related to the control of ventricular response in digitalized patients who had atrial fibrillation or flutter, ventricular rates below 50 at rest occurred in 15% of patients and asymptomatic hypotension occurred in 5% of patients.The following reactions, reported in 1.0% or less of patients, occurred under conditions (open trials, marketing experience) where a causal relationship is uncertain; they are listed to alert the physician to a possible relationship:To report SUSPECTED ADVERSE REACTIONS contact AvKARE at 1-855-361-3993; email drugsafety@avkare.com; or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.Treat all Verapamil overdoses as serious and maintain observation for at least 48 hours (especially Verapamil Hydrochloride Tablets SR), preferably under continuous hospital care. Some drugs can raise or lower your blood levels of verapamil, which may cause side effects or make it less effective. (Maximum: 5 mg/first dose). The usefulness and safety of dosages exceeding 480 mg/day have not been established; therefore, this daily dosage should not be exceeded.

Oral: Extended release capsules (Verelan PM (R)):-Initial dose: 200 mg orally once a day at bedtime (usual dose in clinical trials); in rare cases, initial doses of 100 mg orally once a day at bedtime may be warranted in patients who have an increased response to verapamil (e.g., low-weight patients) Clinically significant hypotensive reactions or high degree AV block should be treated with vasopressor agents or cardiac pacing, respectively. The cardiovascular activity of norVerapamil appears to be approximately 20% that of Verapamil. You may need to use blood pressure medicine for the rest of your life.Store at room temperature away from moisture, heat, and light.Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Effects on male fertility have not been determined.Pregnancy Category C. Reproduction studies have been performed in rabbits and rats at oral doses up to 1.5 (15 mg/kg/day) and 6 (60 mg/kg/day) times the human oral daily dose, respectively, and have revealed no evidence of teratogenicity.

This oral dose has also been shown to cause hypotension in rats. Elsevier Science Verapamil injection is used to rapidly or temporarily restore normal heartbeats in people with certain heart rhythm disorders.

Verapamil HCl is not chemically related to other cardioactive drugs.Inactive ingredients include colloidal silicon dioxide, dibasic calcium phosphate dihydrate, magnesium stearate, microcrystalline cellulose, sodium starch glycolate, light mineral oil, sodium lauryl sulfate, titanium dioxide and hypromellose.Verapamil hydrochloride is a calcium ion influx inhibitor (slow-channel blocker or calcium ion antagonist) that exerts its pharmacologic effects by modulating the influx of ionic calcium across the cell membrane of the arterial smooth muscle as well as in conductile and contractile myocardial cells.Normal sinus rhythm is usually not affected, but in patients with sick sinus syndrome, Verapamil hydrochloride may interfere with sinus-node impulse generation and may induce sinus arrest or sinoatrial block.

Not all possible interactions are listed here.

Verapamil hydrochloride (Verapamil HCl) tablets, USP is a calcium ion influx inhibitor (slow-channel blocker or calcium ion antagonist) available for oral administration in film-coated tablets containing 40 mg, 80 mg or 120 mg of Verapamil hydrochloride.Benzeneacetonitrile, a-[3-[[2-(3,4-dimethoxyphenyl)ethyl] methylamino]propyl]-3,4-dimethoxy-a-(1-methylethyl) hydrochlorideVerapamil HCl is an almost white, crystalline powder, practically free of odor, with a bitter taste. Give a list of all your medicines to any healthcare provider who treats you.Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.Copyright 1996-2020 Cerner Multum, Inc. Available for Android and iOS devices. A review of studies from the past decade indicates that verapamil may be as effective as traditional therapies as prophylaxis for the major types of chronic recurring headache. Asystole should be handled by the usual measures including cardiopulmonary resuscitation.The dose of Verapamil must be individualized by titration. Delayed pharmacodynamic consequences may occur with the sustained-release formulation.